The present invention relates generally to the collection and retention of heat energy and particularly to the collection and retention of heat energy derived from solar radiation.
Solar energy is a virtually inexhaustible energy source; when fossil fuels are no longer available, the sun will continue to make available its energy. While nuclear energy may be provided on a relatively indefinite basis, the environmental cost in the form of hazardous by-products is undesirable. Thus, solar energy is a prime candidate for a long term energy source and there is a need for apparatus which efficiently utilizes this energy source.